Packages with controlled drainage function

ABSTRACT

The present invention is directed to retortable, hot-fill and/or microwavable liquid dispensing packages. The packages include is a line of weakness having a sinusoidal shape in each front and rear panel of the package which are substantially coincident with one another. To drain liquid from the package, a first removable portion can be torn away from the package by manual force separating at the lines of weakness to create a plurality of liquid-passage openings in the remaining portion of the package which extend laterally across the width of the package.

BACKGROUND OF THE INVENTION

The present invention relates generally to primary packaging and more particularly, to retort, hot-fill and/or microwavable packages having a drainage function which enables drainage of liquid from solids from the package.

The following description of the background and embodiments of the invention thereafter is provided to aid in understanding the invention, but is not admitted to describe or constitute prior art to the invention. The contents of the articles, patents, and patent applications, and all other documents and electronically available information mentioned or cited in this application, are hereby incorporated by reference in their entirety to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference, including any references cited in the articles, patents, patent applications and documents cited herein. Applicant reserves the right to physically incorporate into this application any and all materials and information from any such articles, patents, patent applications, or other documents.

Metal cans have been used to hold product contents for some time. More recently, with increases in the costs of metals, such as steel, there has been an interest in providing cans and other forms of containers made of plastic. However, plastic cans and containers have been commonly considered less suitable for some applications due to the physical stresses placed on the material, which for some applications may be significantly greater than those encountered in common plastic container “hot-fill” applications. Flexible containers used for filling processes with warm or hot food products, so called “hot-fill applications”, must address several fundamental concerns that are not present in conventional container applications. The ability to hot fill in sheet or film packages permits the foods to be stored without refrigeration. Commercial sterilization by hot filling imposes several additional restrictions on the choice of materials for the sheet or film structure. The heat seal must survive commercial hot-fill temperatures of above 160° F (71° C.) and typically, between 160° F. to 212° F. (71°C. to 100° C.). The structure must not delaminate, shrink, or wrinkle as a result of the sterilization. The oxygen and water barrier properties must not be permanently adversely affected by the conditions of commercial sterilization. The structure must be adequately strong to permit handling of the package while still hot. The additional requirements imposed by hot filling rule out many of the materials and structures commonly used for non-retort film or sheet food packages.

Retort processes provide an example of applications in which, due to high temperatures and internal pressures, plastic containers have been considered to be undesirable. A common industry objective is to provide a plastic container that can practically withstand such processing with minimal or sufficiently recoverable deformation. A retort pouch may be constructed from a flexible metal-plastic laminate that is able to withstand the thermal processing used for sterilization. The food is first prepared, either raw or cooked, and then sealed into the retort pouch. The pouch is then heated to 240-250° F. (116-121° C.) for several minutes under high pressure inside a retort or autoclave machine. The food inside is cooked in a similar way to pressure cooking. This process reliably kills all commonly occurring microorganisms preventing it from spoiling. The packaging process is very similar to canning, except that the package itself is flexible. The lamination structure does not allow permeation of gases from outside into the pouch. The retort pouch construction varies from one application to another, as a liquid product needs different barrier properties than a dry product, and similarly an acidic product needs different chemical resistance than a basic product.

Many hot-filled and retorted food products are packaged in water or their own natural juices. Typically, liquid is removed from the package before the food product is served. Often, a portion of the package such as an upper corner is torn or cut to form a small opening. If the dimensions of the opening are cut even slightly larger than necessary, then some of the solid contents may be lost through the opening during draining. If the dimensions are excessively small, then draining liquid from the package becomes extremely slow.

Consequently, there exists a desire to, among other things, provide plastic containers having a controlled drainage function which can withstand the physical stresses of a retort, hot-fill and/or microwave cooking processes.

SUMMARY OF THE INVENTION

The present invention is directed to retortable, hot-fill and/or microwavable liquid dispensing packages comprising front and rear panels sealed together at peripheral edges by at least three peripheral seals. Extending laterally the width of each panel is a line of weakness having a sinusoidal shape in each front and rear panel which are substantially coincident with one another. There is also a continuous interior seal positioned between the crests and troughs of the lines of weakness which seals the front panel to the rear panel and extends laterally the width of the panels. The packages further comprise a tear-initiation feature positioned below the first lines of weakness. To drain liquid from the package, a first removable portion can be torn away from the package by manual force separating at the lines of weakness to create a plurality of liquid-passage openings in the remaining portion of the package which extend laterally across the width of the package. The plurality of liquid-passage openings are formed by those portions in each panel defined by the crests and troughs of the sinusoidal-shaped line of weakness which remain below the continuous interior seal after the first removable portion is removed, The number and dimensions of liquid-passage openings can vary depending upon the nature of the product packaged. In some embodiments, controlled drainage is achieved by the designing the dimensions of the liquid-passage openings such that no solid food will pass through these openings. In such embodiments, the relative frequency and/or amplitude of sinusoidal-shaped lines of weakness can be modified to suit a particular food packaging application. In other such embodiments, the location of the continuous interior seal relative to the crests and troughs of the lines of weakness can also be changed to affect the dimensions of the liquid-passage openings. In some embodiments, controlled drainage is achieved by the number of liquid-passage opening which affect the rate of liquid drainage from the package. After draining liquid form the package, the solid contents can be dispensed by tearing a second removable portion away at the tear-initiation feature which creates a singular opening in the package.

In some embodiments, the packages are suitable for retort packaging applications. Such embodiments are applicable for packaging liquids, meats, soups, vegetables, rice, sauces, baby foods, juices, and purees among other things.

In other embodiments, the packages are suitable for hot-fill packaging applications. Such embodiments are applicable for packaging juices, purees, dairy products, sauces, and wine among other things.

In some embodiments, the packages are suitable for microwave cooking where the contents of the packages can be cooked in a microwave oven. After which, the liquid can be drained and contents dispensed.

In other embodiments, the packages are suitable for retort, hot-fill and microwave cooking applications.

It is further contemplated that the packages may have any packaging configuration known in the art, including but not limited to bags, pillow pouches, stand-up pouches, quad pouches, and the like. These and other packaging configurations are well-known in the art.

It is also envisioned that the packages are constructed from packaging materials which are considered a barrier to oxygen and/or moisture. In some embodiments, each panel of the package has an oxygen transmission rate (O₂TR) value of less than or equal to 10 cm³/100 in²/24 hours at 1 atmosphere, 23° C. and 0% RH.

Provided herein are also packaged food products comprising a retortable, hot-fill and/or microwavable food product enclosed within a retortable, hot-fill and/or microwavable liquid dispensing package as disclosed herein.

Further provided herein still are methods for packaging a retortable, hot-fill and/or microwavable food product. The methods comprise: obtaining any retortable, hot-fill and/or microwavable packaging material disclosed herein; and packaging a food product within a retortable, hot-fill and/or microwavable liquid dispensing package as disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring to the drawings, in all of the figures it will be appreciated that dimensions and relative sizes are not to scale but are chosen to illustrate the invention and its various aspects and features.

Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which:

FIG. 1 is a schematic view of a package according to an embodiment.

FIG. 2 is a schematic view another package according to an embodiment.

FIG. 3 is a schematic view of a package in a partially opened state according to an embodiment.

FIG. 4 is a schematic view of a package with t removable portion removed according to an embodiment.

FIG. 5 is a schematic view of a package draining liquid according to an embodiment.

FIG. 6 is a schematic view of a package in a second partially opened state according to an embodiment.

FIG. 7 is a schematic view of a package with a second removable portion removed according to an embodiment.

FIG. 8 is a schematic view of a package laid out to illustrate a plurality of openings formed after a first removable portion is removed according to an embodiment.

DETAILED DESCRIPTION OF THE INVENTION

As used throughout this application, the term “line of weakness” refers to cuts, grooves, scores, or slits in one or more layers of the packaging material used to construct the package panels. As such, the line of weakness does not penetrate through the entire thickness of the panel. Among the advantages of the packages are lines of weakness which do not deleteriously affect the barrier properties of the package even after hot-fill, retort and/or microwave cooking operations. In some embodiments, the lines of weakness have an unrestrained burst strength within the range of 1 psi and 50 psi, or 5 psi and 40 psi, or 10 psi and 30 psi. The unrestrained burst test are well known to those skilled in the art and can be easily replicated without undue experimentation. The packages may include lines of weakness which are continuous, intermittent or continuous and intermittent. Lines of weakness may be formed by any mechanical and/or optical scoring, cutting or perforating methods known in the art. One example of a scoring technique which may be used is optical ablation using a laser source. Laser scoring is well-known in the art.

As used throughout this application, the term “sinusoidal” refers generally to any shape having a “crest” and a “trough”. A “crest” and a “trough” may each be defined as a curved line or angled (“zig-zag”) line. Angled lines include angles of less than 90°. In some embodiments, the amplitude of the crest may equal the amplitude of the trough. In other embodiments, the crest may have a different amplitude as that of the trough. In still other embodiments, the amplitude of the crests and troughs may vary along the length of the line of weakness. The frequency of oscillation of the crest and troughs may also vary and may or may not be repetitive along the length of the line of weakness.

Referring to FIG. 1, the package 10 illustrated is in a pillow pouch packaging configuration having a front panel 21 and a rear panel 22 (not shown). Any hot-fill and/or retort packaging material may be used to form front panel 21 and rear panel 22. In some embodiments, both front and rear panels are each constructed from one of the retort or hot-fill packaging materials described herein. Also depicted in FIG. 1, within package 10 is a food product 100 packaged in liquid 101.

It is envisioned that the front and rear panel may be constructed from any retortable, hot-fill and/or microwavable packaging material. In such embodiments, the front and rear panels may each be formed from the same packaging material or each panel may be formed from different packaging materials.

The front and rear panels may be formed from several laminated packaging materials which may include, but are not limited to the following structures:

(1) 48 gauge (12.19 μm) thick oriented polyethylene terephthalate (OPET) film/print/adhesive/oxygen barrier layer/adhesive/300 gauge (76.2 μm) thick polypropylene (PP) film;

(2) 48 gauge (12.19 μm) thick oriented polyethylene terephthalate (OPET) film/print/adhesive/oxygen barrier layer/adhesive/60 gauge (15.24 μm) thick nylon film/300 gauge (76.2 μm) thick polypropylene (PP) film;

(3) 48 gauge (12.19 μm) thick oriented polyethylene terephthalate (OPET) film/print/adhesive/35 gauge (8.89 μm) thick aluminum foil/adhesive/60 gauge (15.24 μm) thick nylon film/adhesive/300 gauge (76.2 μm) thick polypropylene (PP) film;

(4) 48 gauge (12.19 μm) thick aluminum oxide coated oriented polyethylene terephthalate (OPET) film/adhesive/print/60 gauge (15.24 μm) thick biaxially oriented nylon (BOPA) film/adhesive/300 gauge (76.2 μm) thick polypropylene (PP) film;

(5) 48 gauge (12.19 μm) thick oriented polyethylene terephthalate (OPET) film/print/adhesive/35 gauge (8.89 μm) thick aluminum foil/adhesive/3.5 mil (88.9 μm) thick linear low density polyethylene (LLDPE) film; and

(6) 48 gauge (12.19 μm) thick oriented polyethylene terephthalate (OPET) film/print/adhesive/48 gauge (12.19 μm) thick oriented polyethylene terephthalate (OPET) film/adhesive/3.0 mil (76.2 μm) thick linear low density polyethylene (LLDPE) film.

Non-limiting examples of oxygen barrier materials include plastics such as polyamides (nylon), ethylene vinyl alcohol copolymers, polyvinyl chlorides, polyvinylidene chlorides, metallic coatings, metal oxide coated film, and foils, and glasses. Moisture barrier materials may include, but are not limited to, polyethylene terephthalate copolymers, ethylene norbornene copolymers and high density polyethylenes. Some plastics such as ethylene norbornene copolymers may have both moisture and chemical barrier properties. In each of the aforementioned retort and hot-fill packaging materials, an oxygen barrier layer and/or moisture barrier layer is/are present.

Returning to FIG. 1, in this embodiment, panels 21 and 22 are formed by folding the packaging material in half at fold 40 and sealing the panels at peripheral edges 31, 32, and 33 by three seals 41, 42 and 43. At peripheral edge 34 is a fold 40. In other embodiments, package 10 can include a fourth peripheral seal (not shown) at peripheral edge 34 in place of fold 40. Seals 41, 42 and 43 may be achieved by heat sealing at an elevated temperature under positive pressure, or by applying an adhesive glue to the peripheral margin of the package, or by an ultrasonic welding technique. Each of these sealing methods are well-known to those skilled in the art. The seals will have seal strengths of 386 Wm (1 kg/in) or higher, or 772 N/m (2 kg/in) or higher, or 965 N/m (2.5 kg/in) or higher after the packaging material has been sealed to itself. In such embodiments, the seal strength of the seals may be greater than the tensile strength of one or more of the materials used to form the packaging material. Those skilled in the art can readily determine the seal strength of seals without undue experimentation. A common method of determining seal strength of seals is reported in ASTM F-904 test method.

Package 10 also includes a sinusoidal-shaped line of weakness 51 in front panel 21 and a sinusoidal-shaped line of weakness 52 (not shown) in rear panel 22. Lines of weakness 51 and 52 are substantially coincident with each other being located on opposite sides of and an equal distance from fold 40. The term “coincident” as used herein refers to lines of weakness which lie substantially on top of one another. Each line of weakness includes crests, 51 a and 52 a (not shown) and troughs, 51 b and 52 b (not shown). As depicted, the lines of weakness extend laterally across the width of each panel. Positioned between the crests and troughs of the lines of weakness is a continuous internal seal 44 which seals the front panel 21 to the rear panel 22 and extends laterally across the width of the panels. Continuous internal seal 44 can be formed by heat sealing the inner surfaces of front and rear panels 21 and 22 together. It is contemplated that continuous internal seal 44 may be located any distance below the crests and above the troughs. In this embodiment, package 10 also includes a tear-initiation feature 61 positioned below the lines of weakness. As depicted, the tear-initiation feature 61 can include a notch in a peripheral edge of the package. In other embodiments, tear-initiation feature 61 may include a second line of weakness in each front and rear panel (not shown) which are substantially coincident. In some embodiments, the packages may include two tear-initiation features 61 and 62 as illustrated in FIG. 2. The tear-initiation features can be located at any distance below the lines of weakness. In some embodiments, the second tear-initiation feature 62 is positioned opposite the first tear-initiation feature 61.

FIG. 3 represents package 10 in a partially opened state. In order to dispense liquid from the package, a first removable portion 71 is grasped and pulled away from the package. It is necessary only to grasp the first removable portion 71 and the bottom of the package and exert a pulling or transverse tearing action to open the package. When this is done, first removable portion 71 separates along the lines of weakness 51 and 52 and continuous internal seal 44 as shown in FIG. 4 thereby creating a plurality of liquid-passage openings 80. Tests indicate that curvilinear sinusoidal-shaped lines of weakness facilitate tearing of first removable portion 71 away from the package compared to straight (zig-zag) sinusoidal-shaped lines of weakness. Liquid 101 can be readily dispensed without loss of solid food 100 as shown in FIG. 5. Wherever the portion of the lines of weakness 51 and 62 are above the continuous internal seal 44, the front and rear panels remain sealed together while those portions of the lines of weakness below continuous internal seal 44 create an individual liquid-passage opening. For illustrative purposes only, FIG. 8 shows the plurality of liquid-passage openings 80 formed by the portion of the lines of weakness below the continuous internal seal 44 in package 10 after first removable portion 71 is removed and package 10 is laid open by rupturing seals 41, 42 and 43. It should be noted that the plurality of liquid-passage openings 80 include at least two individual liquid-passage openings. Accordingly, the number of individual liquid-passage openings may vary between 2 and 200, or between 2 and 100, or between 2 and 50, or between 2 and 25. The size of the individual liquid-passage openings can be controlled by the length of line of weakness below continuous internal seal 44, e.g. the amplitude of the lines of weakness above continuous internal seal 44. The number of individual liquid-passage openings can be varied by the relative frequency of the lines of weakness across the width of the panels. In some embodiments, the plurality of liquid-passage openings 80 each have an elliptical shape. In other embodiments, the plurality of liquid-passage openings 80 each have a circular shape.

Turning now to FIG. 6, after draining liquid form the package, a second removable portion 72 can be torn away at the tear-initiation feature 61 by exerting a transverse tearing action in a direction opposite the tear-initiation feature. If two tear-initiation features are present, the tearing action can be opposite to either tear-initiation feature. After the second removable portion 72 is removed, a singular opening 90 is created in the package through which the solid food contents 100 of the package can be dispensed when the first removable portion 71 has been removed from the package. In some embodiments, the singular opening 90 is larger than one of the individual opens of the plurality of liquid-passage openings 80. In such embodiments, singular opening 90 extends the entire width of the panels and between the two side seals 41 and 43. In other embodiments, singular opening 90 extends less than the entire width of the panels.

Packages as described herein lend themselves to mass production on conventional packaging machinery such as, but not limited to continuous and intermittent vertical and horizontal form-fill-seal packaging equipment by those skilled in the art.

The above description and examples illustrate certain embodiments of the present invention and are not to be interpreted as limiting. Selection of particular embodiments, combinations thereof, modifications, and adaptations of the various embodiments, conditions and parameters normally encountered in the art will be apparent to those skilled in the art and are deemed to be within the spirit and scope of the present invention. 

1. A liquid dispensing package comprising: front and rear panels sealed together at peripheral edges by at least three peripheral seals; a line of weakness having a sinusoidal shape in each front and rear panel which are substantially coincident and extend laterally the width of each panel; a continuous interior seal positioned between the crests and troughs of the sinusoidal-shaped lines of weakness which seals the front panel to the rear panel and extends laterally the width of the panels; a first tear-initiation feature positioned below the lines of weakness: a first removable portion which separates at the first lines of weakness and creates a plurality of liquid-passage openings; and a second removable portion which separates at the tear-initiation feature to create a singular opening when the first removable portion has been removed from the package.
 2. A liquid dispensing package according to claim 1, wherein the lines of weakness are continuous.
 3. A liquid dispensing package according to claim 1, wherein the lines of weakness are intermittent.
 4. A liquid dispensing package according to claim 1, wherein the tear-initiation feature is a notch in a peripheral edge of the package.
 5. A liquid dispensing package according to claim 4, further comprising a second tear-initiation feature.
 6. A liquid dispensing package according to claim 5, wherein the second tear-initiation feature comprises a notch in a peripheral edge of the package opposite the first tear-initiation feature.
 7. A liquid dispensing package according to claim 1, wherein the tear-initiation feature is a second line of weakness in each front and rear panel which are substantially coincident.
 8. A liquid dispensing package according to claim 1, wherein the at least three peripheral seals are each a heat seal.
 9. A liquid dispensing package according to claim 1, wherein the continuous interior seal is a heat seal.
 10. A liquid dispensing package according to claim 1, wherein the plurality of liquid-passage openings each have an elliptical shape.
 11. A liquid dispensing package according to claim 1, wherein the plurality of liquid-passage openings each have a circular shape.
 12. A liquid dispensing package according to claim 1, wherein the singular opening extends laterally the width of each panel.
 13. A liquid dispensing package according to claim 1, wherein the lines of weakness each have a depth of less than the entire thickness of the panel.
 14. A liquid dispensing package according to claim 1, wherein the singular opening is larger than one of the plurality of liquid-passage openings.
 15. A liquid dispensing package according to claim 1, wherein the panels each comprise a film having a barrier layer formed from a material selected from the group consisting of polyimide, ethylene vinyl alcohol copolymer, polyvinyl chloride, polyvinylidene chloride, glass, metal foil, metal oxide coated film, thermoplastic polyurethane, polyethylene terephthalate copolymer and combinations thereof.
 16. A liquid dispensing package according to claim 1, further comprising a fourth peripheral seal.
 17. A liquid dispensing package according to claim 16, wherein the peripheral seals each have a seal strength of at least 772 N/m (2 kg/in).
 18. A liquid dispensing package according to claim 1, wherein the lines of weakness each have an unrestrained burst strength of between 10 psi and 30 psi.
 19. A liquid dispensing package according to claim 1, wherein the package has a stand-up pouch configuration.
 20. A liquid dispensing package according to claim 1, wherein the package has a quad-pack configuration. 